Systems and methods of information backup

Abstract

A system for backing up and restoring information includes at least one storage device, a primary server for granting and denying a global lock to devices requesting access to the at least one storage device and at least one secondary server including internal tables for storing information relating to storage in the at least one storage device, the at least one secondary server requesting a global lock from the primary server, wherein after the global lock is granted by the primary server, the at least one secondary server checks its own internal tables to determine whether access to the at least one storage device can be granted.

1. A system, comprising:
 at least one storage device; 
 a primary server for granting or denying a global lock to devices requesting access to the at least one storage device; 
 a secondary server including first internal tables for storing information relating to storage in the at least one storage device, the secondary server requests a global lock from the primary server, wherein after the global lock is granted by the primary server, the at least one secondary server checks the first internal tables to determine whether access to the at least one storage device can be granted; and 
 wherein if the secondary server determines that access to the at least one storage device can be granted, the secondary server marks at least a portion of the at least one storage device as locked, and stores corresponding information in the first internal tables. 
 
   
   
     2. The system as recited in  claim 1 , wherein if the secondary server determines that access to the at least one storage device can be granted, the secondary server propagates the corresponding information to the primary server and any other secondary servers for storage in second and third internal tables associated with the primary server and the any other secondary servers, respectively, indicating that the portion of the at least one storage device is locked. 
   
   
     3. The system as recited in  claim 2 , wherein after the secondary server propagates the corresponding information to the any other secondary servers, the secondary server releases the global lock so that the global lock is available to the any other secondary servers or the primary server. 
   
   
     4. The system as recited in  claim 3 , wherein after the secondary server releases the global lock, the secondary server begins backing up information into the at least a portion of the at least one storage device or restoring information from the at least a portion of the at least one storage device. 
   
   
     5. The system as recited in  claim 4 , wherein after the secondary server is done backing up into or restoring information from the at least a portion of the at least one storage device, the secondary server again requests the global lock so that the secondary server can update the primary server and the any other secondary servers accordingly. 
   
   
     6. The system as recited in  claim 5 , wherein after the secondary server is again given the global lock, the secondary server sends information to the primary server and the any other secondary servers informing the primary server and the any other secondary servers to update the second and third internal tables, respectively, to unlock the at least a portion of the at least one storage device. 
   
   
     7. The system as recited in  claim 1 , further comprising a network for connecting the at least one storage device, the primary server and the any other secondary servers. 
   
   
     8. The system as recited in  claim 7 , wherein the network comprises a storage area network. 
   
   
     9. A method for granting or denying a global lock to a server, comprising:
 sending from a secondary server to a primary server a request for a global lock, the secondary server including first internal tables for storing information relating to storage in a storage device; 
 determining whether any other servers on the network have the global lock; 
 granting or denying the global lock to the secondary server based on whether the any other servers on the network have the global lock; 
 wherein when the global lock is granted by the primary server, the secondary server checks the first internal tables to determine whether access to the storage device can be granted; and 
 wherein if the secondary server determines that access to the storage device can be granted, the secondary server marks at least a portion of the storage device as locked, and stores corresponding information in the first internal tables. 
 
   
   
     10. The method as recited in  claim 9 , wherein if the secondary server determines that access to the storage device can be granted, the secondary server propagates the corresponding information to the primary server and the any other servers for storage in second and third internal tables of the primary server and the any other servers, respectively, indicating that the portion of the storage device is locked. 
   
   
     11. The method as recited in  claim 10 , wherein after the secondary server propagates the corresponding information to the any other servers, the secondary server releases the global lock so that the global lock is available to the any other servers or the primary server. 
   
   
     12. The method as recited in  claim 11 , wherein after the secondary server releases the global lock, the secondary server begins backing up information into the at least a portion of the storage device or restoring information from the at least a portion of the storage device. 
   
   
     13. The method as recited in  claim 12 , wherein after the secondary server is done backing up into or restoring information from the at least a portion of the storage device, the secondary server again requests the global lock so that the secondary server can update the primary server and the any other servers accordingly. 
   
   
     14. The method as recited in  claim 13 , wherein after the secondary server is again given the global lock, the secondary server sends information to the primary server and the any other servers informing the primary server and the any other secondary servers to update the second and third internal tables, respectively, to unlock the at least a portion of the storage device. 
   
   
     15. The method as recited in  claim 9 , wherein the network comprises a storage area network. 
   
   
     16. A computer recording medium storing computer executable code, to cause a computer to execute the steps of:
 sending from a secondary server to a primary server a request for a global lock, the secondary server including first internal tables for storing information relating to storage in a storage device; 
 determining whether any other servers on the network have the global lock; 
 granting or denying the global lock to the secondary server based on whether the any other servers on the network have the global lock; 
 wherein when the global lock is granted by the primary server, the secondary server checks the first internal tables to determine whether access to the storage device can be granted; and 
 wherein if the secondary server determines that access to the storage device can be granted, the secondary server is controlled to mark at least a portion of the storage device as locked, and store corresponding information in the first internal tables. 
 
   
   
     17. The computer recording medium as recited in  claim 16 , wherein the computer executable code also causes the computer to execute the steps of, if the secondary server determines that access to the storage device can be granted, controlling the secondary server to store corresponding information in the first internal tables and propagating the corresponding information to the primary server and the any other servers for storage in second and third internal tables of the primary server and the any other servers, respectively indicating that the portion of the storage device is locked. 
   
   
     18. The computer recording medium as recited in  claim 17 , wherein after the secondary server propagates the corresponding information to the any other servers, the secondary server releases the global lock so that the global lock is available to the any of other servers or the primary server. 
   
   
     19. The computer recording medium as recited in  claim 18 , wherein the computer executable code also causes the computer to execute the steps of controlling the secondary server, so that after the secondary server releases the global lock, the secondary server begins backing up information into the at least a portion of the storage device or restoring information from the at least a portion of the storage device. 
   
   
     20. The computer recording medium as recited in  claim 19 , wherein the computer executable code also causes the computer to execute the steps of controlling the secondary server, so that after the secondary server is done backing up into or restoring information from the at least a portion of the storage device, the secondary server again requests the global lock so that the secondary server can update the primary server and the any other servers accordingly. 
   
   
     21. The computer recording medium as recited in  claim 20 , wherein the computer executable code also causes the computer to execute the steps of controlling the secondary server, so that after the secondary server is again given the global lock, the secondary server sends information to the primary server and the any other servers informing the primary server and the any other secondary servers to update the second and third internal tables, respectively, to unlock the at least a portion of the storage device.